Electrophoretic deposition and characterization of boehmite coatings on titanium substrate

Boehmite aqueous sol was prepared by the peptization of Al(OH)3. The solid phase, obtained by drying the prepared aqueous sol, was characterized by infrared spectroscopy and X-ray diffraction (pseudoboehmite was confirmed), thermogravimetric analysis (the water content in the pseudoboehmite solid phase and the starting formula of pseudoboehmite, Al2O3·1.82H2O, were calculated) and scanning electron microscopy. The influence of the applied voltage and deposition time on the electrophoretic deposition of boehmite coatings on titanium from aqueous sol was investigated. The deposition was performed at constant voltage between 1.0 and 10 V and for a constant deposition time between 10 and 30 min. An increase in the applied voltage and deposition time increased the mass of the boehmite deposit, as well as the amount of evolved hydrogen, causing a more porous structure. It was shown that boehmite coatings of maximum thickness, low porosity and good adhesion can be formed at lower deposition voltage and longer deposition time.